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4,729 result(s) for "flock"
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Biosecurity Assessment and Seroprevalence of Respiratory Diseases in Backyard Poultry Flocks Located Close to and Far from Commercial Premises
Raising backyard chickens is an ever-growing hobby in the United States. These flocks can be a substrate for respiratory disease amplification and transmission to commercial facilities. Five hundred fifty-four chickens from 41 backyard flocks were sampled in this study. ELISA kits were used to detect antibodies against avian influenza (AI), infectious laryngotracheitis (ILT), Newcastle disease (ND), infectious bronchitis (IB), Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS). All visited flock owners answered a biosecurity questionnaire that assessed biosecurity measures. The questionnaire revealed that backyard poultry owners lack simple biosecurity measures such as use of dedicated shoes, their chicken sources are unreliable, and few of them benefit from veterinary oversight. Only one flock had a clear vaccination history against ND and IB. ORT, ND, IB, MS, MG, and ILT were the most seroprevalent in backyard poultry flocks with 97% (41/42), 77.5% (31/40), 75% (30/40), 73% (31/42), 69% (29/42), and 45% (19/42), respectively. The vaccinated flock was not considered in these calculations. When examining the distance between backyard flocks and the nearest commercial poultry facility, ND and MG were significantly more likely to be found in backyard flocks close to (<4 miles) whereas ORT was significantly more likely in backyard chickens located far from (>4 miles) commercial poultry. Birds purchased directly from National Poultry Improvement Plan hatcheries showed a reduced ND, MG, and MS antibody prevalence. Wearing dedicated shoes decreased MS antibody-positive birds. Finally, history of wild bird contact had a clear effect on an increased seroprevalence of NDV and MG. Serological results suggest that backyard poultry flocks have the potential to serve as a reservoir or amplifier for poultry respiratory diseases. The information generated in this project should direct extension efforts toward emphasizing the importance of small flock biosecurity and chick acquisition sources.
The link between broiler flock heterogeneity and cecal microbiome composition
Abstract Background Despite low genetic variation of broilers and deployment of considerate management practices, there still exists considerable body weight (BW) heterogeneity within broiler flocks which adversely affects the commercial value. The purpose of this study was to investigate the role of the cecal microbiome in weight differences between animals. Understanding how the gut microbiome may contribute to flock heterogeneity helps to pave the road for identifying methods to improve flock uniformity and performance. Results Two hundred eighteen male broiler chicks were housed in the same pen, reared for 37 days, and at study end the 25 birds with highest BW (Big) and the 25 birds with lowest BW (Small) were selected for microbiome analysis. Cecal contents were analyzed by a hybrid metagenomic sequencing approach combining long and short read sequencing. We found that Big birds displayed higher microbial alpha diversity, higher microbiome uniformity (i.e. lower beta diversity within the group of Big birds), higher levels of SCFA-producing and health-associated bacterial taxa such as Lachnospiraceae , Faecalibacterium , Butyricicoccus and Christensenellales, and lower levels of Akkermansia muciniphila and Escherichia coli as compared to Small birds. Conclusion Cecal microbiome characteristics could be linked to the size of broiler chickens. Differences in alpha diversity, beta diversity and taxa abundances all seem to be directly associated with growth differences observed in an otherwise similar broiler flock.
Ecology and Evolution of the African Great Lakes and Their Faunas
The Great Lakes of East Africa are collectively the earth's most remarkable and species-rich freshwater feature. Intrinsic biological factors and extrinsic ecological opportunities allowed much of the lakes' spectacular biological diversity to evolve through evolutionary (often adaptive) radiation and explosive speciation. Beyond evolutionary patterns and processes that led to this remarkable biodiversity and its astonishing morphological disparity, we highlight ecosystem functioning and complex biotic interactions such as coevolution. Comparative biogeographic patterns for vertebrates and invertebrates are discussed, as are patterns of diversity and disparity through the late Cenozoic. We demonstrate that the African Great Lakes, because of excellent fossil archives, are a phenomenal setting to integrate micro- and macroevolution. Unfortunately, these amazing ecosystems are also subject to various anthropogenic stressors at global and regional scales, which have already impacted their stability and threaten part of their extraordinary biodiversity with extinction.
A Framework for Malicious Traffic Detection in IoT Healthcare Environment
The Internet of things (IoT) has emerged as a topic of intense interest among the research and industrial community as it has had a revolutionary impact on human life. The rapid growth of IoT technology has revolutionized human life by inaugurating the concept of smart devices, smart healthcare, smart industry, smart city, smart grid, among others. IoT devices' security has become a serious concern nowadays, especially for the healthcare domain, where recent attacks exposed damaging IoT security vulnerabilities. Traditional network security solutions are well established. However, due to the resource constraint property of IoT devices and the distinct behavior of IoT protocols, the existing security mechanisms cannot be deployed directly for securing the IoT devices and network from the cyber-attacks. To enhance the level of security for IoT, researchers need IoT-specific tools, methods, and datasets. To address the mentioned problem, we provide a framework for developing IoT context-aware security solutions to detect malicious traffic in IoT use cases. The proposed framework consists of a newly created, open-source IoT data generator tool named IoT-Flock. The IoT-Flock tool allows researchers to develop an IoT use-case comprised of both normal and malicious IoT devices and generate traffic. Additionally, the proposed framework provides an open-source utility for converting the captured traffic generated by IoT-Flock into an IoT dataset. Using the proposed framework in this research, we first generated an IoT healthcare dataset which comprises both normal and IoT attack traffic. Afterwards, we applied different machine learning techniques to the generated dataset to detect the cyber-attacks and protect the healthcare system from cyber-attacks. The proposed framework will help in developing the context-aware IoT security solutions, especially for a sensitive use case like IoT healthcare environment.
The contribution of the \Darwin Initiative\ collection in the Lake Baikal benthic diatom survey
The joint Russian-British collection \"Darwin Initiative. Benthic samples of Lake Baikal\", was established at the end of the 1990s. Here we briefly overview the data on the survey of the Lake Baikal coastal diatom diversity obtained exclusively using the materials from the collection and methods of light and scanning electron microscopy. The collection contains over 500 initial samples taken at 53 stations of the lake littoral zone from depths 1–20 m. Studying the samples Russian and foreign algologists have identified many new for science diatom taxa, including over 20 genera and 750 species. Data on the collection survey are published in six monographs and atlases, and more than 20 scientific papers. The observed patterns of diversity, distribution, and levels of endemicity in different taxa of Lake Baikal benthic diatoms are discussed.
The formation of “mega‐flocks” depends on vegetation structure in montane coniferous forests of Taiwan
A mixed‐species bird flock is a social assemblage where two or more bird species are moving together while foraging and might benefit from increased foraging efficiency and antipredator vigilance. A “mega‐flock,” which includes flocking species from different vegetation strata, often exhibits high species diversity. Mechanisms for the formation of mega‐flocks have not yet been explored. In this study, we evaluated the influence of vegetation structure and bird species diversity in driving the occurrence of mega‐flocks. We investigated the composition of mixed‐species flocks, local bird communities, and vegetation structure in five vegetation types of two high‐elevation sites in central Taiwan. Mega‐flocks occurred more frequently in pine woodland than later successional stages of coniferous forests. However, species richness/diversity of local bird communities increased along successional stages. Therefore, vegetation variables exhibit more influence on the occurrence of mega‐flocks than local bird communities. Besides foliage height diversity, understory coverage also showed positive effects on flock size of mixed‐species flocks. Our results indicated that pine woodlands with more evenly distributed vegetation layers could facilitate the interactions of canopy and understory flocks and increase the formation of mega‐flocks and thus the complexity of mixed‐species flocks. Mega‐flocks occurred most frequently in pine woodland and decreased in later successional stages of coniferous forests in alpine Taiwan. However, species diversity of local bird communities increased along successional stages. Therefore, vegetation variables exhibit more influence on the occurrence of mega‐flocks than local bird communities.
The bacterial symbiont Wolbachia induces resistance to RNA viral infections in Drosophila melanogaster
Wolbachia are vertically transmitted, obligatory intracellular bacteria that infect a great number of species of arthropods and nematodes. In insects, they are mainly known for disrupting the reproductive biology of their hosts in order to increase their transmission through the female germline. In Drosophila melanogaster, however, a strong and consistent effect of Wolbachia infection has not been found. Here we report that a bacterial infection renders D. melanogaster more resistant to Drosophila C virus, reducing the load of viruses in infected flies. We identify these resistance-inducing bacteria as Wolbachia. Furthermore, we show that Wolbachia also increases resistance of Drosophila to two other RNA virus infections (Nora virus and Flock House virus) but not to a DNA virus infection (Insect Iridescent Virus 6). These results identify a new major factor regulating D. melanogaster resistance to infection by RNA viruses and contribute to the idea that the response of a host to a particular pathogen also depends on its interactions with other microorganisms. This is also, to our knowledge, the first report of a strong beneficial effect of Wolbachia infection in D. melanogaster. The induced resistance to natural viral pathogens may explain Wolbachia prevalence in natural populations and represents a novel Wolbachia-host interaction.
functions of vocal learning in parrots
Given that both sexes of most parrots learn new vocalizations throughout life and produce them in diverse social contexts, whereas few songbird species combine all these traits, why are parrots not a better model for the evolution of human speech than songbirds? We first note the technical constraints that have limited research on wild parrot communication and then review the discoveries that have accumulated in the last two decades as constraints were overcome. Vocal learning in wild parrots appears unrelated to sexual selection and mate competition but is used by parrot pairs to defend nest sites in ways similar to those of songbirds. Where parrots differ from songbirds is in their specialization on toxic and armored foods, the consequences of this diet on foraging and social dynamics, and the use of learned vocalizations to mediate those dynamics. Parrots thus use learned vocalizations for two quite different functions, only one of which they share with songbirds (and hummingbirds). Interestingly, recent neurobiological studies have shown that parrots have dual cortical pathway nuclei for vocal learning, only one of which is present in songbirds. The parallels between the distributions of functions of vocal learning and brain nuclei suggest future research that should clarify both how and why parrots are more extensive vocal learners than songbirds and whether there are in fact parallels with humans.
Seasonal dynamics of flock interaction networks across a human-modified landscape in lowland Amazonian rain forest
Although lowland tropical rain forests were once widely believed to be the archetype of stability, seasonal variation exists. In these environments, seasonality is defined by rainfall, leading to a predictable pattern of biotic and abiotic changes. Only the full annual cycle reveals niche breadth, yet most studies of tropical organisms ignore seasonality, thereby underestimating realized conditions. If human-modified habitats display more seasonal stress than intact habitats, then ignoring seasonality will have particularly important repercussions for conservation. We examined the seasonal dynamics of Amazonian mixed-species flocks, an important species interaction network, across three habitats with increasing human disturbance. We quantified seasonal space use, species richness and attendance, and four ecological network metrics for flocks in primary forest, small forest fragments, and regenerating secondary forest in central Amazonia. Our results indicate that, even in intact, lowland rain forest, mixed-species flocks exhibit seasonal differences. During the dry season, flocks included more species, generally ranged over larger areas, and displayed network structures that were less complex and less cohesive. We speculate that—because most flocking species nest during the dry season, a time of reduced arthropod abundance—flocks are simultaneously constrained by these two competing pressures. Moreover, these seasonal differences were most pronounced in forest fragments and secondary forest, habitats that are less buffered from the changing seasons. Our results suggest that seasonality influences the conservation value of human-modified habitats, raising important questions about how rain forest organisms will cope with an increasingly unstable climate.